lindemann



Aug. 13, 1940. H. E. LINDEMANN AIR CONDITIONING APPARATUS Filed Aug. 50,1937 2 Sheets-Sheet. l

ENTOR. ITZEITU.

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Hm Elincf BY W 67 z ATTORNEY.

13, 1940- H. E. LINDEMANN 2,211,335

AIR CONDITIONING APPARATUS Filed Aug. 30, 1937 2 Sheets-Sheet 2IIIIIIEHIIIIEI 4 1 I I I 4 9 4 'IIIIIIIIIIIIIII 1 v INVENTOR. 4/ 4Herbsrl ELmd'Emann BY I ATTORNEY.

Patented Aug. 13, 1940 ENT QFFICE AIR CUNDITEGNING APPARATUS Herbert E.Lindemann, Milwaukee, Wis, assignor to Perfex Corporation, Milwaukee,Wis., a corporation of Wisconsin Application August 30, 1937, Serial No.161,585

l Claims.

This invention relates generally to air conditioning apparatus but moreparticularly to a unit type air heating and cooling apparatus and theprincipal object of this invention is to pro- 5 vide an improvedapparatus of the foregoing type which is simple and durable inconstruction, easy to assemble and install, and extremely efficient inoperation.

A further object is to provide an improved unit conditioning apparatusin which all unsightly pipe fittings, valves, traps, and other elementsare concealed from View behind the unit, thereby enhancing itsappearance.

A Another object is to provide an improved unit '15 structure in whichthe various parts of the core thereof may expand or contract, inaccordance with varying temperature changes, independent of each other.

A further object of the invention is to provide a core construction foran air conditioning unit in which no soldered, welded or brazed jointsare utilized in assembling the various elements thereof.

An additional object is to provide an improved .25 core construction fora unit apparatus in which the tubes thereof are arranged to provide twopassages of the heating or cooling medium directly in the path of theair stream, resulting in increased efiiciency, and in which the tubesare 3 arranged so as to provide adequate drainage.

A further object is to provide an improved housing or casing for an airconditioning unit together with a support for the same in which allstrains and stresses are removed from the 35 pipes and fittings and fromthe core elements, thereby greatly eliminating the possibility ofleakage.

A particular feature is concerned with an improved header constructionfor the core of a 40 conditioning unit in which the supply and returnheaders are formed integrally whereby the use of seams is eliminated andthe number of joints reduced.

Other objects and advantages reside in certain 45 novel features ofconstruction, arrangement and combination of the parts which will behereinafter more fully described and particularly pointed out in theappended claims.

A preferred embodiment of the invention is il- 50 lustrated in theaccompanying drawings by way of example in the form of an airconditioning apparatus generally known as a unit heater, although theadvantages and features thereof are 55 equally applicable to other typesof air conditioning apparatus such as unit coolers, humidifiers, dryers,etc.

Referring particularly to the drawings, Fig. 1 shows in perspective andon a reduced scale the general outward appearance of a preferred form ofair conditioning apparatus;

Fig. 2 is a top View of the apparatus in section, drawn on a largerscale;

Fig. 3 is a rear view along the lines 3-3 of Fig. 2 with certain partsin section;

Fig. 4 is an end view along the lines 44 of Fig. 2;

Fig. 5 is a fragmentary view showing the header and a portion of thetube arrangement;

Fig. 6 is a cross-sectional elevation showing the header construction;

Fig. 7 is a top View of the header and a portion of the core incross-section;

Fig. 8 is an end view of one of the elements of the core; while Fig. 9is a detailed sectional view of the louver support.

The outer housing or casing for the air conditioning apparatus consistsprimarily of a sheet metal channel shaped top plate I, and a bottomplate 2, together with dished out cast metal side or end plates 3 and 4.The side plates 3 and 4 are formed with outwardly extending flangedportions around their edges and are provided at their top ends with apair of integral cast lugs or projections 5 and a similar pair of lugs 6at their bottom ends. In order to attach the top and bottom cover platesto the side plates the front and rear edges of these plates are providedwith return bent portions which engage the lugs 5 and 6 and are fastenedthereto by the screws 1 which thread into the lugs. The top edges andthe front edge of the side plates are provided with a small flange orlip portion 8 which engages the edges of the top and bottom cover platesin order to more securely bind the plates together and render a morepleasing appearance to the complete housing.

Suitably arranged vertically within the housing is a dual passage castmetal header 9 and a radiator core indicated generally at H. The top ofthe radiator core H is provided with a sheet metal fin guard l2 which ischannel shaped to engage the front and rear sides of the core ii. Asimilar fin guard i3 is arranged on the bottom of core H and is securedto the bottom of the header 9 by bolts M. The end of the radiator corell opposite from the header 9 is provided with a channel shaped tubespacer IS, the top and bottom ends of which are suitably attached as bywelding to the ends of the fin guards I 2 and I3. In order to properlyposition the radiator core within the housing, the side plates 3 and 4are provided with spacing lugs I6 at their top and bottom ends whichengage the top and bottom corners of the core and hold it in its properset position. From the foregoing it will be seen that the fin guards I2and I3 together with the tube spacer I and header 9 form a unitary innerhousing or supporting structure for the core II which enables the coreto be readily removed or replaced and which considerably facilitates theassembly of the apparatus in the housing.

It is customary to support the unit air conditioning apparatus in aposition where it will not interfere with the occupants of a room oroccupy needed space and for this reason the unit may be convenientlysupported from a ceiling or at the top of a wall for example. Forsupporting the unit there is arranged within the casing a relativelyheavy metal supporting bracket I'I, one end of which is secured to thetop end of the header 9 by a bolt I8, while the other end is attached tothe top fin guard I2 by a bolt and nut I9, so that the core is supportedat points which lie in a plane passing through its center of gravity andparallel to the core without straining the same. Other bolts and nuts 2Iand 22 clamp the supporting bracket I'I directly on to the top coverplate I and for supporting the complete unit suitable hanger brackets 23and 24 thread on to the bolts 2I and 22. The hangers provide convenientmeans for attachment of the unit to metal supporting straps or asupporting pipe may be threaded into them if desired. The bolts 2I and22 are arranged in such a manner that the complete air conditioning unitis supported at points which lie in a plane passing through itsapproximate center of gravity and parallel thereto so that its weight isevenly distributed on each Side of the hangers 23 and 24. With theforegoing supporting arrangement it will be seen that the core II issupported from bolts 2| and 22 through bracket I'I independent of thehousing thereby eliminating all stresses or strains to which it might besubjected to. Similarly the housing by its independent support from thecore structure will not be distorted or strained due to the weight ofthe core. In addition the possibility of the connecting or supply pipesof the unit producing leakage due to the weight of the unit, is entirelyeliminated.

In order to force the air to be conditioned through the core II, a fan25 is provided at the rear end of the unit with a motor 26 to drive itat any desired speed. For supporting the fan motor 26 a number of bolts2! are arranged upon a supporting plate 28 which in turn is suitablysecured as by welding to supporting brackets 29 and 3I and braces 32 and33, all integrally welded together. A pair of bolts 34 securely hold theends of supporting bracket 29 to the edges of side plates 3 and 4 whilea further bolt secures the brace 32 to the top cover plate I. In orderto confine the air stream propelled by the fan 25 within the area of theradiator core II, a suitable rectangular fan shroud 35 is provided whichhas a circular opening in which the fan blades revolve. It is held inposition behind the core I I by several screws 36 at the top and bottomof the shroud which thread into the fin guards I2 and I3.

The front of the air conditioning unit is provided with the customaryadjustable louvers 31 which direct the conditioned air in any desireddirection. The louvers are supported in angle brackets 38 and 39 whichare in turn supported by screws 4I threading into the flanged ends ofside plates 3 and 4. The louver supporting brackets 38 and 39 arelikewise arranged to serve as core spacers and together with the lugs I6hold the radiator core in its proper position within the housing byengaging the fin guards I2 and I3. The louvers 31 are supported from theangle brackets 38 and 39 by means of shoulder screws 42 which engageopenings in turned down ends of the louvers. The angle brackets 38 and39 are provided with threaded lugs 43 into which the shoulder screws 42are fastened, and in order to arrange it so that the louvers can beadjusted to any desired angle and remain in their adjusted position, aspring washer 44 is positioned between the lug 43 and the turned downend of the louver. The spring washer together with the somewhatresilient end of the louver presents sufficient frictional engagementfor the elements to hold the louver in its set position.

It has been customary in the past to provide radiator cores withseparate supply and return headers with the connecting tubes arrangedbetween them so that one end of the tubes connected with one header andthe other end with the other header. This arrangement presented numerousdifliculties and was somewhat impractical due to the fact that duringthe use of the unit the tubes were subjected to considerable expansionand contractional strains and stresses which resulted in leakage andbreakage of the tubes, usually at their connecting point with theheaders. In the arrangement according to this invention this diificultyhas been overcome by providing a header in which the supply and returnheader portions are formed or cast into a single unitary structure. Theconnecting tubes are preferably U-shaped and their ends connected to thesingle header thereby permitting variations in contraction and expansionof the tubes to take place at their other end. For the purposes ofillustrating a particular use for the air conditioning unitincorporating the invention it will be assumed that it is connected to asource of steam supply and thereby serves as a unit heater to heat aspace in which it is located. It will be understood however, that anyother medium such as cold water or a refrigerant may be passed throughthe unit and therefor serve to cool the space, or in another of itsapplications hot water instead of steam may serve as the heating medium.As illustrated clearly in Figs. 6 and 7 the header 9 is provided with asupply header chamber 45 which comprises the steam passage and a returnheader chamber 46 which comprises the condensate passage and which isseparated from the supply passage 45 by a par tition 41, there being noconnection for the heating medium between the passages except throughthe connecting tubes. The supply passage 45 is formed somewhat largerthan the return passage 46 due to the fact that the steam passingthrough the passage 45 will be in a somewhat expanded state while thatthrough the return passage 46 may comprise a somewhat cooler medium orcondensate. At the top of the header 9 an inlet port 48 is formedintegral therewith, while at the bottom of the header a similar outletport 49 is provided. The inlet port it will be noted, is of a somewhatlarger diameter than the outlet port 49 consistent with the size of theassociated chambers. Suitable supply and return piping connections maybe threaded into these ports 48 and 49 and it will be observed thatthese connections as well as any additional necessary valves, fittings,or traps are all arranged at the rear side of the air conditioning unitwhere they are concealed from view and where the connections may beconveniently made without disturbing other elements of the unit. Thisarrangement-greatly enhances the general appearance of the unit andrenders it suitable for use in somewhat refined locations.

The he der 9 is provided along one side of the return h ader passage 46with a plurality of integral bosses 5! while the supply passage issimilarly provided along its side with bosses 52. The bosses 5i and 52serve as a means for connecting the ends of a series of transverselyextending U-tubes 53 to the header 9. Each of the U-tubes 53 is arrangedwith one leg 5 1 which is attached to the supply header passage 45 whilethe other leg is attached to the return passage 45 so that two passagesfor the heating medium flowing through the tubes are arranged directlyin the path of the air stream, resulting in increased efiiciency of theunit due to the fact that both the supply and return legs of each tubeare rendered effective.

Referring particularly to Fig. 5 it will be seen that the leg 54 isgradually inclined from a horizontal position at the boss 52 to one endwhere a U-shaped bend 55 is made in each tube which is also inclineddownward as shown clearly in Fig. 4, while the other leg 55 extendsfurther downward from the U-bend 56 to the connecting boss 5|. Theseries of bosses 5i and 52 as seen in Fig. 5 are therefore staggeredalong the header 9 in alternate series. By arranging the tubes 53 inthis manner the expanded steam passes from the passage 15 through theU-tube leg '54 to its end 56 and leg 55, and during this passage hasconsiderable heat extracted from it so that by the time it reaches theend of the return leg 55 the steam is more or less reduced to acondensate. By arranging each leg of the tube at the angle shown, apositive and complete drainage of the condensation from each tube isprovided thereby greatly increasing the heating eificiency and doingaway with the possibility of noisy and destructive water hammer onaccount of accumulated condensation.

In order to securely connect the end of the U-tubes 53 to the header 9 acompression fitting 5'! surrounds the end of each tube leg as shown inFig. '7. The end of the tube is rolled over as indicated at 58 and restsin a seat formed in the bosses 5| and 52 so that by tightly turning inthe compression fitting 51 the rolled portion 58 of the tube is closelyfitted into the seat so that all possibility of leakage at theconnection is eliminated. In addition, by the use of the compressionfittings 51 each individual tube 53 may be removed or replaced withutdisturbing the other tubes so that repairs can be conveniently made.Furthermore, it is seen that the use of solder, welded or brazed jointsbetween the tubes and header is entirely obviated so that this customarysource of leakage is not present in this structure. The use of a singleheader likewise reduces the number of seams or joints which arecustomarily utilized. The return header passage 46 is provid ed with anorifice 59 at the point where each of the return legs connect with theheader. These orifices it will be noted are of approximately the samesize as the inside diameter of the tube legs 55. The supply passage 45is similarly provided with orifices 6| where each of the legs 54 of thetubes extends into the passage. These openings however, are of asomewhat smaller diameter than the openings 59 in the tubes in orderthat the steam supply may be evenly distributed from the supply passage45 in equal amounts to each of the plurality of tubes forming theradiator core, while the orifices 59 are of sufficient larger diameterto adequately carry on the condensation to the return passage 46.

In order to dissipate and carry the effect of the heating medium fromthe tubes a series of fins 62 are arranged along both legs of the tubes.The fins and tubes may be arranged within the air stream generated bythe fan 25 in such a inamier that the row of fins on the leg 55 forexample, are staggered with respect to the row of fins on the leg 55 sothat the air stream has complete and full effective distribution overall of the area of each fin. As shown in Fig. '7 the fins aremechanically bonded to the tubes in any well known manner, as by havinga shoulder portion 63 expanded upon the tubes and as shown in Fig. 8their surfaces are embossed for added mechanical strength in such amanner so as not to produce unnecessary air turbulence. The verticalposition of the fins on the tubes precludes the possibility of dust anddirt settling upon them and where the unit is used as a cooling deviceany accumulated moisture on the fins is readily drained off and notblown into the room. By this provision the efiiciency of the unit is notreduced.

In order to permit a free longitudinal expansion and contraction of thetube 53 the channel shaped tube spacer I5 is provided with a series oftongues M which engage the top and bottom sides of the U-bent portion 56of each tube, thereby providing a sliding surface for each tube topermit its expansion and contraction and which at the same time holdsthe tubes in definite alignment and a definite pitch or angle. In orderto further maintain the ends of the tubes in definite alignedrelationship, a pair of parallel angle brackets 55 and 66 are arrangedperpendicular to the tubes and suitably attached to the channel plate I5as by spot welding. In the foregoing manner each of the tubes 53 is freeto expand and contract longitudinally at one end while being constrainedat the header end. In addition some slight movement may take place atright angles to the axis of the tubes but they are free to expand inthis direction without restraint. It should be noted that the sides ofthe tube spacer l5 encompass the tube bends 55 and thereby protect themfrom injury at all times.

In the foregoing description and the appended claims it is intended thatthe expression center of gravity with reference to the unit and radiatorcore support, shall be construed to mean that these elements aresupported at their approximate center of gravity.

While only a single preferred embodiment of the invention has beenillustrated and described by way of example, it is readily apparent thatvarious modifications of the elements thereof may be devised by thoseskilled in the art and it is therefor desired that the invention be notlimited to the exact disclosure but only to the extent of the appendedclaims.

What is claimed is:

1. In a unit type air conditioning apparatus, 2. 1101151113 comprisingtop and bottom plates together with side plates connecting the ends ofthe top and bottom plates, the front and rear of the housing being open,means for securing all of said plates together, said securing meanscomprising pairs of lugs extending transversely from the top and bottomof each side plate, return bend portions formed along the front and rearedges of the top and bottom plates, said return bend portions engagingsaid lugs so that the lugs lie inside the return bends and within thehousing, and means inside the housing for securing the return bendportions to each of the lugs, radiator core supporting means arrangedwithin the housing independent of the plates, and radiator spacing lugsarranged within the housing at the top and bottom ends of each sideplate.

2. In an apparatus of the class described, a radiator housing comprisingtop and bottom plates and side plates connecting the ends of the top andbottom plates, said housing being open at the front and rear thereof, aprojecting lug extending transversely from the inside top and bottomcorners of each side plate within the housing, return bent portionsformed along the front and rear edges of the top and bottom plates anddefining the top and bottom edges of the front and rear openings of thehousing, each end of a return bent portion engaging one of theprojecting lugs and fastened thereto on the inside of the housing,radiator core spacing lugs extending centrally from the top and bottomends of each side plate within the housing, a flange portion formedaround the edges of each side plate and defining the side edges of thefront and rear openings, the top and bottom flange portions of the sideplates engaging and overlapping the ends of the top and bottom plates,and louver supporting means arranged on each flange portion adjacent thefront housing opening.

3. In a unit type air conditioning apparatus, a housing comprising topand bottom plates together with side plates connecting the ends of thetop and bottom plates, the front and rear of the housing being open,means for securing all of said plates together, said securing meanscomprising pairs of lugs extending transversely from the top and bottomof each side plate, return bend portions formed along the front and rearedges of the top and bottom plates, said return bend portions engagingsaid lugs so that the lugs lie inside the return bends and within thehousing, and means inside the housing for securing the return bendportions to each of the lugs.

4. In a unit type air conditioning apparatus; an outer housingcomprising top and bottom plates having return bent portions formedalong the front and rear edges thereof together with substantiallychannel-shaped side plates having internal projections cooperating withand extending within said return bent portions, internal means forsecuring said return bent portions to said projections whereby all ofsaid plates are rigidly held together; a core unit within the housing;an elongated supporting bracket concealed inside the top plate of theouter housing having ofiset end portions attached to each end of thecore unit for supporting and positioning the same from the outerhousing, means for securing the bracket to the top plate of the outerhousing whereby the weight of the housing and core unit is independentlysupported from the concealed supporting bracket; lugs inside of theouter housing side plate engaged by the core unit to position and spacesaid unit from the back of the outer housing, and a pair of verticalright angle louvre supporting brackets removably attached to the insideedges of the outer housing side plates and acting against said core unitto hold the same against said positioning lugs.

HERBERT E. LINDEL/IANN.

